Sökning: "Lauri Holappa"

Visar resultat 1 - 5 av 15 avhandlingar innehållade orden Lauri Holappa.

1. 1. Model Developments to Study Some Aspects of Improving Efficiencies in EAF Plants

   Författare :Niloofar Arzpeyma; Mikael Ersson; Lauri Holappa; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : The aim of this thesis is to investigate some aspects of improvements with respect to the energy consumption and raw material selection as well as the understanding of the influence of uncertainties on the performance in electric arc furnace (EAF) plants. The effect of electromagnetic stirring on the scrap melting and post combustion capacity are investigated in two EAFs by using computation fluid dynamic (CFD) models. LÄS MER

3. 2. A Study of Slag/Metal Equilibrium and Inclusion Characteristics during Ladle Treatment and after Ingot Casting

   Författare :Hamid Doostmohammadi; Pär Jönsson; Lauri Holappa; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; inclusions; thermodynamics; ladle treatment; vacuum; tool steel; bearing steel; slag; equilibrium; slag carryover; oxides; sulfides.; Metallurgical process engineering; Metallurgisk processteknik;

   Sammanfattning : Today, there is a high demand on clean steel for high performance materialproperties. Thus, steel producers try to deliver a steel product with the highestquality and cleanliness to the market. The number of parameters that affect thesteel cleanliness may vary depending on the required material properties of thefinal product. LÄS MER

4. 3. Evaluations of Non-metallic Inclusionsin Ca-treated Steels and Their Effect on the Machinability

   Författare :Hongying Du; Andrey Karasev; Pär Jönsson; Lauri Holappa; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; non-metallic inclusions; Ca treatment; stainless steel; machinability.; icke-metalliska inneslutningar; kalciumbehandling; rostfritt stål; skärbarhet.; Teknisk materialvetenskap; Materials Science and Engineering;

   Sammanfattning : In recent decades, a considerable development of steel with respect to the performance of steel has taken place, which also has resulted in large challenges to process these steel grades. Therefore, it is essential to make suitable modifications of non-metallic inclusions (NMI) in the steelmaking process and to have a good control of its characteristics to meet the target mechanical properties and to obtain a good machinability. LÄS MER

5. 4. An Experimental Study of a Liquid Steel Sampling Process

   Författare :Ola Ericsson; Andrey Karasev; Pär Jönsson; Lauri Holappa; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; liquid steel sampling; inclusion characteristics; sampling conditions; sample homogeneity.; Metallurgical process engineering; Metallurgisk processteknik;

   Sammanfattning : During the steelmaking process samples are taken from the liquid steel, mainly to assess the chemical composition of the steel. Recently, methods for rapid determination of inclusion characteristics (size and composition) have progressed to the level where they can be implemented in process control. LÄS MER

7. 5. A Study of Different Methods for Inclusion Characterization towards On-line use during Steelmaking

   Författare :Diana Janis; Pär Jönsson; Lauri Holappa; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; on-line method; PDA OES; electrolytic extraction; inclusions; clusters; nozzle clogging; secondary steelmaking;

   Sammanfattning : The interest of gaining on-line information related to non-metallic inclusions during the steelmaking process has recently increased due to the development as well as the promising results of the Pulse Distribution Analysis with Optical Emission Spectroscopy method (PDA/OES). Even though, the time from sampling to presented results on inclusions is only about 5-10 minutes, the method has also shown limitations with respect to the determination of some inclusion characteristics. LÄS MER